Another option is to join the BAA World Points (free membership).

http://www.baa.co.uk/

It offers 100 points upon joining. You can then redeem 50 points for a 50% off one way Heathrow Express, Gatwick Express or Stansted Express. 100 points for both ways.

Nice One Mr MCO!

Yes, RichardinSF, this should be a sticky!

Gatwick Express still has the 4 for 2 deal going. Pay for 2 and 4 can ride. We found people waiting in line for tickets, told them and split the cost. Basicly, half price. Check the www.gatwickexpress.com page.

I had given the dates I intended to travel and my return was about 10 days later than my arrival. When I got to LHR and put in my credit card, it spewed out the two tickets VERY quickly. Good thing I read the tickets, because the return expired three days after issuance!

I went to the ticket booth, where often you have to wait in line, and the guy stamped it as good until my return date. He said this is a problem with buying two one ways that they kept bugging the website people about and that I had needed to buy a round trip. But as I recall, the 25% discount only applied to the one way fare.

So if the HEX discount is valid, I suggest you make all round trip purchases as separate transactions and then pick up your ticket just before departure by using the specific transaction code for that direction to avoid having to wait in line at the ticket counter.

Of course, that is significantly more hassle. Poor website design, they must be taking lessons from ual.com..... :)

Definitely take advantage of this:

Help yourself to a free glass of champagne at Chez Gerard
Why not treat yourself to the best steak frites this side of the channel before you fly? There’s a free glass of champagne waiting for you at Chez Gerard (Terminal Three departures).
To get your free glass of fizz, simply show your Heathrow Express ticket to your waiter or waitress.

No need to make this a sticky, alas, the promo pages are gone (at least for me this morning)!!!!

Oh no!!! Am I supposed to pay full fare now??? :D

It still works.

And, if you refer someone, you get 250 points the first time they use their card. I just referred my wife.

I just tried it again, from the US this time, and still get "page does not exist." Wonder what the difference is that made it work for you?

Instead of clicking on the link provided by the OP - just go to the regular GEX website and do a booking - and type in the promo code provided by the OP.

I tried a dummy booking earlier today for GEX and I can still see the discounted fare.

I just tried that for HEX and it worked. Hurrah, but a bit too late for my trip just completed. I had tried just that the first time I found that PROMO went away and it didn't work. But my earlier try was from Stockholm and this try was from the U.S. It is certainly possible that it could take that into consideration -- it would know the IP address where the request was coming from.

Thanks Mr MCO for the BAA tip. However, similar to what Roger points out, the online acknowledgement of booking indicates that only 50% of the one-way fare will be charged to your card (GBP6.75 in the case of HEX) but the email acknowledgement states that the full fare will be charged. Interesting!!! I have sent an email to point this out and will post the outcome when I receive an answer.

I think the price quote is for the normal price of the tik but right above that on the email it states "50% discount".

I think you'll be OK. I just did this and I'm going to check my VISA bill just in case though.

The discount is indeed 50% on GEX & HEX
 

As described above I wrote to them and here is their response (I have included only the HEX response. The GEX response was identical. Both signed by John Corbyn, Gatwick Express.)

All's well ^ and thanks again for the tip :D